A feeding device includes a plurality of driving modules, a plurality of feeding modules and a plurality of couplers. Each driving module has a driving shaft pivotally mounted on a housing and driven by a power module to be rotated about an axis. Each feeding module includes a pivoting shaft substantially coaxial with the driving shaft, a suspending unit journalled on the pivoting shaft to be pivotable and having a bearing portion which is disposed to be biased downwardly by a spring member, a driven shaft mounted rotatably on the bearing portion, and a feeding roller driven by the driven shaft. Each coupler includes a transmitting shaft having two ends connected to the driving shaft and driven shaft by universal joints, respectively.